Hypokalemia

Synonyms of Hypokalemia

Hypokalemic Syndrome

Hypopotassemia Syndrome

Low Potassium Syndrome

Nephritis, Potassium-Losing

Potassium Loss Syndrome

General Discussion

Hypokalemia is a metabolic imbalance characterized by extremely low potassium levels in the blood. It is a symptom of another disease or condition, or a side effect of diuretic drugs. The body needs potassium for the contraction of muscles (including the heart), and for the functioning of many complicated proteins (enzymes). Potassium is found primarily in the skeletal muscle and bone, and participates with sodium to contribute to the normal flow of body fluids between the cells in the body. The normal concentration of potassium in the body is regulated by the kidneys through the excretion of urine. When the kidneys are functioning normally, the amount of potassium in the diet is sufficient for use by the body and the excess is usually excreted through urine and sweat. Body chemicals and hormones such as aldosterone also regulate potassium balance. Secretion of the hormone insulin, which is normally stimulated by food, prevents a temporary diet-induced Hypokalemia by increasing cell absorption of potassium. When Hypokalemia occurs, there is an imbalance resulting from a dysfunction in this normal process, or the rapid loss of urine or sweat without replacement of sufficient potassium.

Signs & Symptoms

Most often, hypokalemia is asymptomatic, with no obvious signs of the disorder. However, symptoms of hypokalemia may include attacks of severe muscle weakness, eventually leading to paralysis and possibly respiratory failure.

Muscular malfunction may result in paralysis of the bowel, low blood pressure, muscle twitches and mineral deficiencies (tetany). Severe hypokalemia may also lead to disruption of skeletal muscle cells, particularly during exercise. The normal physical response to exercise requires the local release of potassium from muscle. In potassium depleted muscle, the lack of potassium prevents adequate widening of blood vessels, resulting in decreased muscle blood flow, cramps and the destruction of skeletal muscle.

Hypokalemia may also impair the ability of the kidneys to concentrate urine, resulting in excessive urination (polyuria) and excessive thirst (polydipsia). Other symptoms may include loss of appetite, nausea and vomiting. There may also be heart irregularities seen in electrocardiograph changes, confusion, distention of the abdomen, a decrease in mental activity.

Causes

Hypokalemia always occurs as a result of excessive loss of potassium through the urine, sweat or stool. It is always a symptom of another disorder, rather than a disease that occurs by itself.

The excessive excretion of potassium in the urine (kaliuresis) may result from the use of diuretic drugs (which increases urination), a deficiency of magnesium in the blood, excessive mineralocorticoids such as aldosterone in the blood which affect the electrolyte and fluid balance in the body (usually caused by endocrine diseases), kidney disorders, or from the use of high doses of penicillin. Gastrointestinal losses of potassium usually are due to prolonged diarrhea or vomiting, chronic laxative abuse, inadequate dietary intake of potassium, intestinal obstruction or infections such as fistulas in the intestines which continually drain intestinal fluids. Additionally, excessive perspiration due to hot weather or exercise can cause hypokalemia.

Affected Populations

Hypokalemia may affect both males and females. However, it occurs more commonly in females.

Related Disorders

Symptoms of the following disorders include Hypokalemia. Comparisons may be useful for a differential diagnosis:

Bartter’s Syndrome is a metabolic disorder involving the kidneys. Major symptoms include slowed growth, weakness, excessive thirst and excessive urination. Bartter’s Syndrome is characterized by the excessive loss of potassium through the kidneys. (For more information on this disorder, choose “Bartter” as your search term in the Rare Disease Database.)

Periodic Paralysis, Hypokalemic Type, is a disorder characterized by episodes of paralysis with loss of deep tendon reflexes and failure of muscles to respond to electrical stimulation. The cause is unknown. The paralysis may be limited to certain muscle groups or it may affect all four limbs. The attacks usually last between 24 and 48 hours. Potassium levels are usually abnormally low (hypokalemia).

(To find other disorders that include Hypokalemia as a symptom, choose “Hypokalemia” as your search term in the Rare Disease Database.)

Standard Therapies

The underlying cause of Hypokalemia must first be treated. When the hypokalemia is severe, potassium chloride may be administered orally or intravenously. Treatment must be carefully monitored by a physician. Any associated acid-base disorders or hormonal disturbances must be evaluated before treatment is planned. The administration of potassium and potassium- sparing diuretics is usually discouraged in patients with kidney disease, diabetes mellitus, or dysfunctions of the autonomic nervous system. The imbalance of external and internal potassium levels in these individuals may predispose them to life-threatening degrees of Hyperkalemia (too much potassium). Hypokalemia in individuals with high blood pressure taking diuretics may be improved by replacing lost potassium in the diet through certain fruits or potassium drugs. Hypokalemia may also be minimized by dietary restriction of salt since high rates of sodium excretion promote urinary potassium losses. People who participate in vigorous sports or exercise in warm weather should be sure to replace potassium that is lost through excessive sweating. This can be accomplished through dietary planning.

Investigational Therapies

Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.

For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:

Tollfree: (800) 411-1222

TTY: (866) 411-1010

Email: prpl@cc.nih.gov

For information about clinical trials sponsored by private sources, contact:

NORD's Rare Disease Database provides brief introductions for patients and their families to more than 1,200 rare diseases. This is not a comprehensive database since there are nearly 7,000 diseases considered rare in the U.S. We add new topics as we are able to do so, with the help of rare disease medical experts.

If you are seeking information about a rare disease that is not in this database, we would suggest contacting the Genetic and Rare Diseases Information Center (GARD) at the National Institutes of Health. NIH has the most complete database of rare diseases in the U.S.

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